Problems with regression tests

I've been looking on the mailing lists for this problem, but haven't found
anything yet. My apologies if I'm not looking in the right place.

System:
Linux Kernel 2.1.108 (but occurs under 2.0.33 as well)
Glibc 2.0.7pre3
Bash 2.02

Problems:
(1) Compiles. Installs. But when running regression tests, postmaster
attempts to execute bash (/bin/sh) with "-c" option. Comes back with "sh:
option '-c' requires an argument" and the call fails. Was able to get
PostgreSQL installed and functional with Glibc 2.0.6 libraries (but
complained of several regression failures, which appeared to be due to the
well-known rounding bug).

(2) Not necessarily a problem, but I noticed that postmaster is linked
against both libc-5 and glibc-2. Output from ldd:
libcrypt.so.1 => /lib/libcrypt.so.1 (0x40002000)
libnsl.so.1 => /lib/libnsl.so.1 (0x4002f000)
libdl.so.1 => /lib/libdl.so.1 (0x40035000)
libm.so.6 => /lib/libm.so.6 (0x40038000)
libreadline.so.2 => /usr/lib/libreadline.so.2 (0x40053000)
libtermcap.so.2 => /lib/libtermcap.so.2 (0x40070000)
libncurses.so.4 => /usr/lib/libncurses.so.4 (0x40073000)
libc.so.6 => /lib/libc.so.6 (0x400b3000)
libc.so.5 => /lib/libc.so.5 (0x40157000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x2aaaa000)

System started out as RedHat 4.1, with many, maaaaany hand-compiled
upgrades (libraries, kernels, utilities, etc.). Everything works up to
this point. Also, no other programs that I've compiled since the library
upgrade link against both libc.so.6 and libc.so.5.

Suggestions?